Communications equipment that carries out communication within network having plural pieces of communications equipment

ABSTRACT

When data transmission is to be conducted between a master station and a slave station, the master station moves the other slave stations to such a park mode (standby state) that they do not make a communication request. Thus the master station and the slave station can conduct data transmission from and to each other with priority use of a communication network. After completion of the data transmission process, the master station sends each slave station a notification of release of the communication network to return each slave station to the normal operating state.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to communications equipment thatcarries out communication within a network having plural pieces ofcommunications equipment.

[0003] 2. Related Background Art

[0004] A conventional network formed with plural pieces ofcommunications equipment, especially a network based on the Bluetoothstandard employing a frequency hopping wireless communications systemforms a piconet from one master station and one to seven slave stationson a network basis. This type of network provides communications using apolling system. The polling system is such that the master station orone of the slave stations can exclusively use the network for a fixedperiod of time called a slot. In other words, the master station selectsa slave station as its communication partner in a slot, and the selectedslave station sends a response back in the next slot.

[0005] The above-mentioned conventional communication system, that is,the polling communication system, however, requires the master stationto carry out polling communications with all the slave stations. As thenumber of slave stations in the network increases, the allocation ofslot dedicated to each slave station is reduced, compared to a casewhere the slave stations are few in number, which reduces thecommunication capacity and hence the effective transmission speed ofeach slave station.

[0006] Further, in such a wireless communication network, since manypieces of communications equipment, especially of portable informationequipment, are battery-operated, the reduction in effective transmissionspeed results in a falling ratio of effective communications toequipment operating time.

SUMMARY OF THE INVENTION

[0007] It is an object of the present invention to prevent a fallingratio of effective communications to operating time of communicationsequipment within a network.

[0008] It is another object of the present invention to place highpriority to a piece of equipment that is making a communication request.

[0009] It is still another object of the present invention to realizelow power consumption of communications equipment.

[0010] Other objects of the present invention will become apparent fromthe following specification and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is an overview of a wireless communication network 1 havingcommunications equipment according to an embodiment of the presentinvention;

[0012]FIG. 2 is a flowchart showing an operation process of a masterstation at data transmission executed in the wireless communicationnetwork 1 according to embodiments of the present invention; and

[0013]FIG. 3 is a flowchart showing an operation process of a slavestation executed in the wireless communication network 1 according tothe embodiments of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Embodiments of the present invention will now be described indetail with reference to the accompanying drawings.

[0015] (First Embodiment)

[0016]FIG. 1 is an overview of a wireless communication network havingcommunications equipment according to an embodiment of the presentinvention.

[0017] In FIG. 1, a wireless communication network (radio LAN) 1 isformed with plural pieces of communications equipment havingcommunications capabilities. The wireless communication network 1provides Bluetooth-compliant wireless communications between pieces ofcommunications equipment to form a piconet based on the Bluetoothstandard. In general, the piconet is such that a piece of communicationsequipment becomes a master station, and one to seven pieces ofcommunications equipment as slave stations intercommunicate with themaster station. According to the network reference model, communicationis made possible only between the master station and a slave station atthe level of the physical layer, that is, slave stations cannot directlycommunicate with each other. In this case, the piconet includes thefollowing pieces of communications equipment having radio communicationscapabilities: a digital camera 2, a network-ready printer 3, computers 4and 5, and portable information equipment (PDA: Personal DigitalAssistant) 6.

[0018] Description will be made next about an operation process of amaster station at data transmission executed in the wirelesscommunication network 1 of FIG. 1. The following describes a case wherethe master station in the above-mentioned piconet is the digital camera2, and the slave stations are the printer 3, the computers 4, 5, and thePDA 6.

[0019]FIG. 2 is a flowchart showing the operation process of the masterstation at data transmission executed in the wireless communicationnetwork of FIG. 1.

[0020] In FIG. 2, it is assumed that an operator of the digital camera 2operates an operation part on the digital camera 2 to instruct thedigital camera 2 to perform printing on the printer 3 as one of theslave stations. Upon receipt of the instruction, the digital camera 2has a negotiation process before data transmission with the printer 3that is one of the slave stations (step S2). In this process, thedigital camera 2 refers to the printer 3 for the presence of printingpaper, the residual quantity of ink, operating status of anotherprinting job and so on, to judge whether there is any problem. If thereis no problem, the digital camera 2 notifies the printer 3 that thedigital camera 2 starts sending printing data to the printer 3. Thisprocess allows the printer 3 not to move to a standby state (park mode)as specified in the Bluetooth scheme even upon receiving a broadcastingrequest from the digital camera 2 in the next step 3.

[0021] Next, the digital camera 2 performs a broadcasting process forpriority use of the network for all the slave stations within thewireless communication network 1. In this process, the digital camera 2informs the printer 3, the computers 4, 5 and the PDA 6 that thewireless communication network 1 is just going to be used forcommunication between the digital camera 2 and the printer 3 with highpriority (step 3). To be more specific, the digital camera 2 sends eachslave station a broadcasting message of transition to the park mode(notification of priority use of the network). Upon receipt of thebroadcasting message, each slave station is moved to the park mode inwhich the slave station does not make a request for communication, thuslimiting each slave station's use of the wireless communication network1. In this case, however, the digital camera 2 has already had thenegotiation process with the printer 3 in the above-mentioned step 2.Therefore, the printer 3 to receive printing data from the digitalcamera 2 does not move to the park mode even upon receiving thebroadcasting message of transition to the park mode.

[0022] Next, the digital camera 2 performs a data transmission processto send printing data to the printer 3 with priority use of the wirelesscommunication network 1 (step 4). After completion of the datatransmission process, the digital camera 2 as the master stationperforms a broadcasting process to inform each slave station of releaseof the wireless communication network 1 (step S5), and it ends theoperation process. To be more specific, the digital camera 2 sends eachslave station a broadcasting message of a request for return to a normalmode (notification of network release) to return each slave station fromthe park mode to the normal operating state.

[0023]FIG. 3 is a flowchart showing an operation process of each slavestation at data transmission executed in the wireless communicationnetwork 1 of FIG. 1.

[0024] In FIG. 3, when the operation process is started, each slavestation judges whether the received message is the notification ofpriority use of the network (step S11). As a result of judgement, if thereceived message is not the notification of priority use of the network,the operation process is ended. Even when the received message is thenotification of priority use of the network, if no negotiation processbefore data transmission has not been conducted before the notificationis received, each slave station performs a process for transition to thepark mode (step S12). To be more specific, each slave station moves tothe park mode (standby state) in which the slave station itself becomesa low power consumption state without making a communication request tothe wireless communication network 1. In other words, each slave stationchanges its operating state to the park mode in response to the requestfor transition to the park mode from the master station as specified inthe Bluetooth scheme.

[0025] It should be noted that the slave station (the printer 3 in theembodiment) that have had the negotiation process before datatransmission with the digital camera 2 as the master station does notmove to the park mode even upon receiving the notification of priorityuse of the network.

[0026] Next, each slave station performs in the park mode a broadcastingmonitoring process for the wireless communication network 1 (step S13).In the park mode as specified in the Bluetooth scheme, since each slavestation is synchronized with the wireless communication network 1, itreceives a message notified (broadcast) at each park interval. Then,each slave station judges whether the received message is thenotification of network release (step S14). As a result of judgement, ifthe received message is not the notification of network release, eachslave station returns to step S13 from which it repeats the operationprocess again. On the other hand, if the received message is thenotification of network release, each slave station performs a processfor return to the normal operation mode (step S15), and then it ends theoperation process. After completion of this process, each slave stationenters such a state that it can communicate with the master station.

[0027] It should be noted that the first embodiment described such acase where the digital camera 2 is the master station in the piconet,but the printer 3 may be the master station. Further, the communicationsequipment is not limited to the above-mentioned equipment. For example,the communications equipment may be a portable telephone, a headset, alaptop computer, a facsimile and so on, as long as they have radiocommunications capabilities.

[0028] According to the above-mentioned first embodiment, it is assumedthat printing data is to be transmitted from the digital camera 2 as themaster station to the printer 3 as one of the slave stations. In thiscase, the digital camera 2 moves all the slave stations but the printer3 to the park mode (standby state) in which they do not make a requestfor communication through the wireless communication network 1 (step S12in FIG. 3). After completion of data transmission to the printer 3 withpriority use of the wireless communication network 1, the digital camera2 notifies each slave station of release of the wireless communicationnetwork I to return each slave station to the normal operating state(step S15 in FIG. 3). Thus the digital camera 2 as the master stationand the printer 3 as one of the slave stations exclusively use thenetwork during data transmission, which improves data transmissionefficiency, and hence reduces data transmission time, compared to theconventional technique. Further, in the park mode (standby state) basedon the Bluetooth scheme, each slave station is synchronized with thewireless communication network 1 to check a broadcasting packet such asa beacon transmitted from the master station at each park interval.After receiving the broadcasting packet, each slave station in the parkmode, has only to perform synchronization compensation. This makes itpossible to reduce power consumption of each slave station for radiocommunication processing, and hence the total power consumption of thewireless communication network 1 in which plural slave stations are inthe park mode.

[0029] It should be noted that the first embodiment described the parkmode as a standby state in the Bluetooth scheme, but the presentinvention may also use one of the other standby states in the Bluetoothscheme, namely a sniff or hold mode, instead of the park mode. Since anyof the standby states, the sniff, park or hold mode, is the mode of lowpower consumption in the Bluetooth system, any mode can reduce powerconsumption of each slave station for radio communication as mentionedabove.

[0030] (Second Embodiment)

[0031] The second embodiment is different from the first embodiment inthat the transmission of data is performed between the digital camera 2and the printer 3 both as slave stations through the PDA 6 as the masterstation. It should be noted that the second embodiment has the samestructure as the first embodiment except that the master station is thePDA 6, and therefore, description thereof will be omitted.

[0032] It is assumed in FIG. 2 that the digital camera 2 as one of theslave stations makes a request to the PDA 6 as the master station forpriority use of the network together with the printer 3 as another slavestation for data transmission. Upon receipt of the request, the PDA 6has the negotiation process before data transmission with the digitalcamera 2 and the printer 3 (step S2). Then the PDA 6 performs thebroadcasting process for priority use of the network to inform eachslave station within the wireless communication network 1 of priorityuse of the wireless communication network 1 (step S3). This processmakes each slave station move to the park mode (standby state) in whichthe slave station does not make a request for communication, thuslimiting each slave station's use of the wireless communication network1. In this case, however, the digital camera 2 and the printer 3 towhich printing data are transmitted from the digital camera 2 do notmove to the park mode even upon receiving the request for transition tothe park mode from the PDA 6 as the master station. In other words, onlypieces of the communications equipment other than the PDA 6, the digitalcamera 2 and the printer 3, namely the PC 4 and 5 as the other slavestations within the wireless communication network 1, move to the parkmode during the transmission of printing data.

[0033] Next, the digital camera 2 transmits printing data to the printer3 through the PDA 6 with priority use of the wireless communicationnetwork 1 (step S4). After completion of the data transmission process,the PDA 6 as the master station performs the broadcasting process toinform each slave station of release of the wireless communicationnetwork 1 (step S5), and it ends the operation process. To be morespecific, the PDA 6 sends each slave station the broadcasting message ofthe request for return to the normal mode (notification of networkrelease) to return each slave station from the park mode to the normaloperating state.

[0034] In the second embodiment, operations of the other slave stationswhen notified that the digital camera 2 and the printer 3 both as slavestations use the wireless communication network 1 with high priority,and that the wireless communication network 1 is released are the sameas those in the first embodiment. It should be noted that thecommunications equipment is not limited to the above-mentionedequipment, and a portable telephone, a headset, a laptop computer, afacsimile and so on may also be used as long as they have radiocommunications capabilities.

[0035] In the second embodiment, when slave stations pair up for datatransmission, the data transmission process is performed through anotherpiece of communications equipment as the master station. Therefore,pieces of communications equipment operating during the transmission ofdata are three in number, that is, the master station and two slavestations. Since the number of operating stations increases, the totalpower consumption of the wireless communication network 1 increasescompared to that in the first embodiment. However, the first embodimentneeds a process for changing the master station in the wirelesscommunication network 1, that is, in the piconet, in order to set oneequipment as the slave station and the other as the master station. Incontrast, the second embodiment does not need such a process to changethe master station, which reduces time to be spent on this process.

[0036] According to the above-mentioned second embodiment, it is assumedthat printing data is transmitted from the digital camera 2 to theprinter 3 both as slave stations through the PDA 6 as the masterstation. In this case, the PDA 6 moves all the slave stations but thedigital camera 2 and printer 3 to the park mode (standby state) in whichthey do not make a request for communication through the wirelesscommunication network 1 (step S12 in FIG. 3). After completion of datatransmission from the digital camera 2 to the printer 3 with priorityuse of the wireless communication network 1 (step S4 in FIG. 2), the PDA6 notifies each slave station of release of the wireless communicationnetwork 1 to return each slave station to the normal operating state(step S15 in FIG. 3). This makes it possible to improve datatransmission efficiency, and hence reduces data transmission time,compared to the conventional technique.

[0037] It should be noted that, like the first embodiment, the secondembodiment described the park mode as a standby state in the Bluetoothscheme, but the present invention may also use one of the other standbystates in the Bluetooth scheme, the sniff or hold mode, instead of thepark mode.

[0038] As described above, the present invention can prevent reductionin efficiency of use of a communication line in a network, and hencereduce communication time.

[0039] Further, the communications equipment that is to carry outcommunication can keep its normal operating state even upon receivingthe notification of priority use of the network, which makes it possibleto give the equipment preference on use of the communication line in thenetwork.

[0040] The other pieces of communications equipment that have not hadthe predetermined negotiation process with the master station move tosuch an operating state that they do not make a communication requestupon receiving the notification of priority use of the network. On theother hand, they return to the normal operating state upon receiving thenotification of network release. Therefore, the communicationsequipment, especially in the event of battery-operated portableinformation equipment, can carry out long-time communication withoutreducing the efficiency of effective communications to the operatingtime.

[0041] Further, the communications equipment moves to such a state thatit does not make a communication request, which makes it possible toreduce the total power consumption of the network.

What is claimed is:
 1. A network having plural pieces of communicationsequipment comprising: a first notification means for notifying priorityuse of said network to the communications equipment within said network;and a second notification means for notifying release of said network tothe communications equipment within said network after completion ofcommunication with priority use of said network.
 2. The networkaccording to claim 1, wherein the communications equipment that hasreceived the notification from the first notification means changes itsmode according to whether it carries out communication with priority useof said network.
 3. The network according to claim 2, wherein the modechange is a change to such a mode that the communications equipment doesnot make a communication request.
 4. The network according to claim 3,wherein upon receiving the notification from said second notificationmeans, the communications equipment is released from the mode in whichthe communications equipment does not make a communication request. 5.The network according to claim 2, wherein the mode change is a change toa mode of low power consumption.
 6. The network according to claim 1,wherein the notification from said first notification means and saidsecond notification means is carried out by a control station.
 7. Thenetwork according to claim 1, wherein the communications equipmentcarries out communication based on the Bluetooth scheme. 8.Communications equipment comprising: a first notification means fornotifying other pieces of communications equipment that thecommunications equipment carries out communication with priority use ofa network; and a second notification means for notifying release of thenetwork to the other pieces of communications equipment after completionof the communication with priority use of the network.
 9. Thecommunications equipment according to claim 8, wherein the notificationfrom said first notification means is to change the pieces ofcommunications equipment that do not carry out communication withpriority use of the network to such a mode that they do not make acommunication request.
 10. The communications equipment according toclaim 9, wherein the notification from said second notification means isto release the pieces of communications equipment from such a mode thatthey do not make a communication request.
 11. The communicationsequipment according to claim 8, wherein the notification from said firstnotification means is to change the pieces of communications equipmentthat do not carry out communication with priority use of the network toa mode of low power consumption.
 12. The communications equipmentaccording to claim 8, wherein said communications equipment carries outcommunication based on the Bluetooth scheme.
 13. A network having pluralpieces of communications equipment comprising: a communication meansthat provides data communication between pieces of communicationsequipment; and a changing means that changes the mode of the otherpieces of communications equipment that do not carry out datacommunication during the communication through said communication means.14. The network according to claim 13, wherein said changing meanschanges the mode by broadcasting a predetermined notification to theplural pieces of communications equipment within said network.
 15. Thenetwork according to claim 13, further comprising a negotiation meansthat makes one piece of communications equipment negotiate with theother piece of communications equipment with which the one piece ofcommunications equipment carries out data communication, wherein saidchanging means changes the mode of all the pieces of communicationsequipment but the pieces of communications equipment that havenegotiated with each other through said negotiation means.
 16. Thenetwork according to claim 13, wherein said changing means changes themode of the other pieces of communications equipment that do not carryout data communication to such a mode that they do not make acommunication request.
 17. The network according to claim 13, whereinsaid changing means changes the mode of the other pieces ofcommunications equipment that do not carry out data communication to amode of low power consumption.
 18. Communications equipment comprising:a communication means that carries out data communication with at leastone other piece of communications equipment; and a changing means thatchanges the mode of the other pieces of communications equipment that donot carry out data communication during the communication through saidcommunication means.
 19. The communications equipment according to claim18, wherein said changing means changes the mode by broadcasting apredetermined notification to all pieces of communications equipmentwithin a network.
 20. The communications equipment according to claim18, further comprising a negotiation means that makes one piece ofcommunications equipment negotiate with the other piece ofcommunications equipment with which the one piece of communicationsequipment carries out data communication, wherein said changing meanschanges the mode of all the pieces of communications equipment but thepieces of communications equipment that have negotiated with each otherthrough said negotiation means.
 21. The communications equipmentaccording to claim 18, wherein said changing means changes the mode ofthe pieces of communications equipment that do not conduct datatransmission to such a mode that they do not make a communicationrequest.
 22. The communications equipment according to claim 18, whereinsaid changing means changes the mode of the pieces of communicationsequipment that do not conduct data transmission to a mode of low powerconsumption.
 23. Communications equipment comprising: a communicationmeans that provides data communication; and a changing means thatchanges its own mode according to whether said communication meanscarries out communication on the basis of information received fromanother piece of communications equipment.
 24. The communicationsequipment according to claim 23, wherein the determination as to whethercommunication is carried out through said communication means is made onthe basis of whether said communications equipment have negotiated withanother before data communication.
 25. The communications equipmentaccording to claim 23, wherein said changing means changes the mode ofits own to such a mode that the communications equipment does not made acommunication request.
 26. The communications equipment according toclaim 23, wherein said changing means changes the mode of its own to amode of low power consumption.
 27. A control method for a network havingplural pieces of communications equipment, comprising: a firstnotification step of notifying the plural pieces of communicationsequipment within said network of priority use of said network; and asecond notification step of notifying the plural pieces ofcommunications equipment of release of said network after completion ofcommunication with priority use of said network.
 28. A control methodfor communications equipment, comprising: a first notification step ofnotifying priority use of a network to other pieces of communicationsequipment; and a second notification step of notifying release of saidnetwork after completion of communication with priority use of saidnetwork.
 29. A control method for a network having plural pieces ofcommunications equipment, comprising: a communication step of providingdata communication between pieces of communications equipment; and achanging step of changing the mode of other pieces of communicationsequipment that do not carry out data communication during thecommunication in said communication step.
 30. A control method forcommunications equipment, comprising: a communication step of providingdata communication with at least one other piece of communicationsequipment; and a changing step of changing the mode of other pieces ofcommunications equipment that do not carry out data communication duringthe communication in said communication step.
 31. A control method forcommunications equipment, comprising: a communication step of providingdata communication; and a changing step of changing the mode of its ownaccording to whether communication is carried out in said communicationstep on the basis of information received from another piece ofcommunications equipment.